public class Main {
  public static void main(String[] args) {
    Animal animal = new Dog();
    animal.shout();
    animal.run();
  }
}
class Animal {
  void shout() {
    System.out.println("animal shout！");
  }
  public void run() {
  }
}
class Dog extends Animal {
  void shout() {
    super.shout();
    System.out.println("wangwang……");
  }
  public void run() {
    System.out.println("Dog is running");
  }
}